Electric switching device



Jan. 10, 1939. J. G. JACKSON ELECTRIC SWITCHING DEVICE Filed Dec. 27, 1 934 3 Sheets-Sheet 1 INVENTOR. ,J LJDHN G. d-ncmsou fie Jan. 10, 1939. J. G. JACKSON ELECTRIC SWITCHING DEVICE Filed Dec. 27, 19:54 3 Sheets-Sheet 2 m A w 5 mmvrox.

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BY v l ATTORNEY.

Patented Jan. '10, 1939 UNITED STATES PATENT OFFICE anaemic swrrcmno navrcs 7 John G. Jackson; Detroit, Mich, assignor a Square D Company, Detroit, Mich, a corporation of Michigan Application December 27, 1934, Serial No. 759,354 so Claims. (clf zoo-o) a switching device in which the switching unit is mounted forwardly of the rear wall of an enclosing cabinet to provide a wiring space there between.

Another object of this invention is to provide a switching device in which a switching unit is mounted forwardly of the rear wall of the enclosing cabinet to provide a wiring space and in which the unit is readily demountable to provide unobstructed access to said wiring space.

Another object of this invention is to provide a switching unit having operating mechanism mounted thereon and readily detachable from an operating handle secured to an enclosing cabinet I to provide readydemountability to the switching I unit. Another object of this invention is to provide an improvedconstruction of switching unit having a reciprocable switching element providing for a multiple break and having arc suppressing features. I

Another object of this invention is an improved electric switch construction.

Further objects and features of the invention will be readily apparent to those skilled in the art from the following specification and the ap:- pended drawings illustrating certain preferred embodiments of the invention in which:-

Figure 1 is a perspective view of a switching device according to the present invention with the cover closed.

Figure 2 is a front elevational view of a switching device according to present inventionwith the coveropen and showing one manner of wiring the device. I

Figure 3 is a transverse sectional view corresponding to that taken on line III-1110i Fig- 50 'ure 2 with the cover closed.

Figure 4 is asectional view taken on .the line IV-IV-of Figure 3. Figure 5 is a sectional view taken on the line v-v onFisiire '4.

Figure 6 is a sectional view taken on the line VI--VI of Figure 4 with parts broken away to more clearly show the operating mechanism.

iReferring now to the different figures of the drawings'in which like reference numerals indi- 60 cate like parts in the various figures, the emthe edge of the cover member.

to provide bodiment of the invention as illustrated comprises a cabinet I having a box like body portion 2 and a cover 3 hinged as at 4, l to the body portion. The top and bottom and one side of said cover member are flanged as at 5 to enclose the corresponding sides of the body portion of the cabinet. The opposite side of said cover member extends adjacent to but short of the fourth side of the body portion. This side of the body portion is provided-with a flange or strip .6 beneath the edge of cover member 3. This strip 8 may be a flange integral with the side of the cabinet or may be a strip otherwise secured thereto. A narrow trimming strip 1 extends along strip 6 from the edge of the cover to the side of the cabinet and is provided with enclosing flanges 8 to give a flnished appearance to the outside of the cabinet. Strips 8 and 1 are provided with a slot 8 closely adjacent 'to the side of the cabinet, one edge of said slot extending along Within said slot a flat plate like handle portion II is disposed.

. This handle portion is pivoted'to the side of the cabinet as at l2. The handle portion H is provided with a grippingextension l3 for manipulating the switching elements. A latching de-- vice i4 is secured to the wall of the cabinet and projects through a slot ,in the cover member to latch it in closed position. Secured to the rear wall of the cabinet and extending forwardly thereof are mounting posts II disposed in pairs adjacent the top and bottom of the cabinet and slightly closer to the side of the cabinet opposite to the one upon which the handle member is pivoted, the pair of posts at the top of the cabinetbeing spaced closer together than those at the bottom. A guard element I 6 is disposed in the cabinet adjacent to the rear-wall thereof and encloses the lower portion of the operating handie and the parts of the operating mechanism projecting below the base of the switching unit to be hereinafter described. The rear wall of the cabinet is provided with the usual attaching holes for securing the cabinet in position.

The switching unit comprises a metallic supporting member ll having a flat base plate and upstanding sides. I cured to said base plate and is provided at one end with a rabbet portion I! more particularly shown by the open space in Figure 5. The vertical wall of the base member adjacent to the rabbet portion is provided with plurality of slots 2|, 22, II, 24,2! and 26, alternate ones of which' the slots are provided with curved portions 21, 28.

A plurality of contact members 28 are secured An insulating base I8 is seto the base and have fingers-projecting into alternate slots, the ends of the fingers being curved to conform to the curvature 271 on the walls of the slots. At the underside of the supporting plate bearing brackets 3i are provided in which are pivoted the ends of .an operating bar 32 extending through slots 33 in the supporting plate forwardly around the front of the rabbet portion of the base block. The front surface of the rabbet portion is provided with guiding grooves 3 in which are disposed guide lugs 35 on an insulating contact bar 36. A metallic U-shaped bracket 37 is secured to the bottom of the bar 3% and is provided with slotted portions loosely and removably engaging the operating bar 32.

On the top of the insulating bar are disposed a-plurality of U-shaped contact members 38, each leg of which is disposed opposite one of the slots of the base block. Enclosing each of said contact members is a U-shaped clip 39 of a spring material such as steel to maintain the position of the contact fingers and to exert the desired contact pressure between movable and stationary contact members.

A metallic supporting bracket ii for the cover member is secured to the base plate at the bottom thereof. The unit is provided with an insulating cover member 62 which is supported on the top of the base and on the bracket fill. This cover member has cooperating pairs of fuse clips 33 mounted thereon, the upper clips of each pair being electrically and mechanically attached to contact members fl l which extend within the alternate slots 22, 2d and 2%, from the front thereof. and which are curved to form with the curvature 28 on the walls of the slots. The top of the cover is cut away as at as to provide access to terminals Qt attached to contact members 29. The lower fuse clips of each pair are connected to terminals fill. It is. of course. understood that if an unfused switch is desired contacts id and terminals il are directly connected by conducting strips on the front of the cover 2. The cover member is attached to the supportin base plate b studs 38. 58 which pa s throu h the base block and screw into threaded holes in the base plate and is further. secured by. studs 49. 49 which are screwed into bracket member ii. The unit is demountablv attached to mountin posts i5 by studs iii. 5i which extend through the cover plate and bear against the front of the base block tonermit removal of the cover while the base block is mounted in position. The base plate is secured to the lower mounting posts by studs 52, 52 which pass through openingsin extensions on said plate.

'The operating mechanism for the switching elements is shown as mounted on an upstanding .side of the supporting base plate. This operating mechanism compr ses a pair of concentric pivoted discs 53 and 54, disc 55 having a'projecting portion 55 extending throu h an arcuate slot 56 in the side wall and provided with a notch 57 engaging the operating bar 32. Disc 56 is provided with'another and oppositely extending lug portion 58 which is received within an arcuate notch 53 in disc 53. A post 5| projects from the side of the disc 53 and is adapted for engagement with a notch in the operating handle to be hereinafter described. A plunger 52 is attached to an edge of disc 53 and extends through a slot in member 63 secured on the side of the supporting plate. A compression spring 64 is disposed surrounding said plunger 62 between element 53 and-disc 53. It is seen fromthis description oi amass? the parts that disc 53 will have a considerable rotation tending to compress the spring 64 without moving disc 56 or bar 32. When, however, the rotation of disc 53 becomes suflicient to move the'then compressed spring t6 past its dead cen- 5 ter which occurs when the plunger 62 isin line with the pivot for the disc tt the energy of the spring will be expended in quickly continuing the rotation of the disc 53. By this time a side of notch 59 has engaged with lug 58 so that disc 56 is also quickly moved with disc 53 under the action ofv spring 1. This moves operating bar 32 and the switching bar 36 to move the contacts t8 quickly within the slots and into engagement with the associated contacts 29 and 4d. 15 The reverse movements of these parts occur in a similar manner which provides a quick break. A flat plate-like handle portion ii is provided with a notch $5 for engagement with post 6i, thenotch portion being wide enough to provide for movement free of the operating handle after spring t t passes dead center in either direction. An interlock comprising a pivoted spring urged member 58 is disposed on the .side wall of the a cabinet and has a latching surface t7 engaging a 25 wall 38 on the handle portion and preventing operation of said handle into switch on position when the .cover is removed. The cabinet cover 3 is provided with an L-shaped depending portion as which, as the cover is closed, passes through the slot ii in the cabinet. The foot of the L engages a ing it on the member 58 and rotates it counterclockwise as shown in Figure 6, thus moving the latching surface til out of engagement with the wall 68 on the handle. This 35 rotation of the member 86 moves the locking lug l2 thereon over the foot of the L, as also shown in Figure 6. Movement of the switch handle into the on position places the large circular portion of the handle alongside the member 66. In this position the handle positively prevents the clockwise rotation of the member 66 under its spring bias and if it is attempted to raise the cover 3 while the switch is on, the foot of the L-shaped member 69 will engage with the locking lug T2 and prevent opening of the cover. When the switch is in the oil position the handle will be in the position shown in Figure 6 and as the cover is raised member 66 is free to rotate clockwise under its springbias, thus moving the locking 50 lug 72 out of the path of the foot of the L-shaped member 69, whereupon the cover may be freely moved to its open position. Provision is also made for disabling this interlock and permitting opening of the cover while the switch is in the on position when desired. As shown in Figure 1, a portion of the slot 12 is exposed while the cover is closed. By the insertionof a screwdriver or other tool in this exposed portion of the slot. the member 66 may be further rotated counterclockwise against its spring bias until the back portion of the locking lug 12 has passed beyond the path of the foot of the L-shaped member 69 whereupon the cover may be opened although theswitch is in its on position. In the bottom corner of the cabinet is provided a spring 13 havinitial movement of said handle toward ofl" position. An insulating sheet ii is disposed between the side of the base plate on which operating mechanism is mounted and the base block it.

The mounting of the switching element as a readily demountable unit spaced forwardly of the rear wall of the cabinet provides a wiring space between the base of theunit and the cabinet free from moving parts which might interfere with wires disposedtherein. One method of wiring a switch in accordance with present invention is shown in Figure 2, the wires leading to the lower terminals being disposed behind the base of the switching unit. Thedemountability of the unit provides a means of easy access to the back of the cabinet and facilitates the pulling of the wires through the conduits attached to the cabinet. At the same time the cabinet construction according to the present invention is adapted to provide a maximum of accessibility to the interior, of the cabinet portion with the desired front projecting handle, it being noted that with the cover removed almost the entire front face of the cabinet is exposed. The improved switching unit also facilitates the ready removalof the operating parts from the cabinet, the post 6| being readily removable from the slot 65 in the handle as the .unit is moved to the left to uncover the large openings permitting passage of the heads of studs 52. The curvature of the contact elements 29 and 44 provides a wiping action with the movable contact elements 28. The restricted openings into the slots in which the stationary contacts are disposed provides a'desirable arc suppressing construction. The extensions of slots 2i, 23 and 25 to the top of the block constitute vents for the arc gases. It is noted that each circuit is broken in two points which further facilitates the quenching of the arc. The elements of the unit are also constructed with the purpose in view of providing for ready removal and replacement of the parts.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that theinvention is not limited thereto as many variations will bereadily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of .the following claims.

I claim: v

1. In an electric switching device, a box-like cabinet having an open top, a narrow strip extending along one side of the top of said box, a narrow, elongated opening in said strip, a narrow, flat handle member extending through said opening and a hinged cover for said box enclosing three sides-thereof and extending to said strip on the fourth.

2. In a switching device, a box-like cabinet open at the front, a narrow cover strip extendingalong one side of said cabinet from top to bottom,

a narrow opening in said strip, an operating handle having a flat portion extending through said ,opening and a grip portion exterior to said cabinet, and a movable cover for said cabinet extending to its three sides and said cover strip.

3. In a switching device, a box-like cabinet having an open front, a movable closure for said cabinet extending fully to three sides thereof and short of but closelyadjacent to the fourth side for at least a portion of its length, a narrow flange on said fourth side extending under said closure,

a slot in said flange with one side thereof closely adjacent to the edge of the closure, and an operating handle having a narrow, flat portion extending through said slot.

4. In 'a' switching device, a bpx-like cabinet having an open top, a movable closure for said cabinet extending fully to three sides thereof and short of but closely adjacent to the fourth side extending fully to three sides thereof and short.

of but closely adjacent to the fourth side for. at least a portion of its length, a narrow strip extending from said fourthside beneath the adiacent edge of said closure, the top of said strip being level with the top of the box, a narrow trimming strip extending along said first mentioned strip from the edge of the closure to the fourth side, the strips having a narrow, elongated slot therethrough for aprojecting handle member, the closure and trimming strip having flanges overlapping the sides of the cabinet.

6. In an electric switching device a box-likecabinet having an open top, a hinged cover for said cabinet having flanges on three sides thereof, the fourth side being unflanged' for at least a portion of its length and having said'unfianged portion terminating a small distance short of the adjacent side of the cabinet, a narrow top strip extending along the side of the cabinet and beneath the adjacent edge of the cover, the top of said strip being level with the top of the cabinet, a slot in said strip, a narrow, flat, handle portion passing through said slot, a side of the slot extending along the unflanged portion of the cover, and a narrow, trimming, cover member extending on said strip from the cover to the side of the cabinet, thetrimming cover member being flanged to complement the unflanged portion of the cover to effect an orderly appearance of the exterior of the cabinet, said trimming cover member being slotted to conform with the slot in the strip.

7. In a switching device, a box-like cabinet having an opentop, a. narrow strip extending along one side of the top of said box and having a narrow, elongated slot therein, a narrow, flat, handle member, extending through said slot,

a hinged cover for said box inclosing three sides thereof and extending to said strip on the fourth, a switching unit mounted in said cabinet forwardly of the rear wall thereof and having an operative'connection with said handle, said unit being readily detachable from said cabinet and handle to provide access to the cabinet interior.

'8. In a switching device, a cabinet, switch operating means disposed on a stationary part of' and extending to the exterior of said cabinet ad- Jacent one side thereof, a switching unit mounted 'in said cabinet forwardly 'of the rear wall thereof,

said unit having switching mechanism normally cooperating with and readily removable from said operating means, the space between said unit and said rear wall being free of projecting moving parts; and said unit being readily demountable .tact members when its fingers are inserted into the slots, and a cover for said base member spaced above the path of movement of said bar.

10. A switching unit including an insulating base member having slots therein, a stationary contact member disposed in each of said'slots, a reciprocable U- shaped contact member disposed with a finger opposite each of said slots, means for reciprocating said ill-shaped member, a portion of the slots adjacent to the entrance thereof being restricted to provide arc suppressor surfaces, and a cover for said base member, at least one of said contacts being carried by and removable with said cover.

11. A switching unit including an insulating base having a rabbet portion in its front face at one end thereof, a reciprocable switching element disposed in said portion, slots in the wall of said base adjacent to said portion, a contact attached to the base and extending into one of the slots, a removable cover for said base, and a con- .tact supported on said cover member and extending into another slot, said switching element bridging said contacts when inserted into said slots.

12. A switching unit comprising a supporting plate, an insulating base mounted thereon, slots in said base, a stationary contact member in each of said slots, contact fingers insertable into said slots, an insulating carrier for said contact fingers, an operating bar pivoted on said plate, means for loosely and detachably connecting said carrier to said bar, and an insulating cover for said base carrying circuit protective receiving means connected to certain of said stationary contacts, said cover cooperating with the said base to prevent access to the switching parts.

13. A switching unit including an insulating base member having slots therein, a stationary contact member disposed in each of said slots, a re- I ciprocable insulating member having contact fing'ers mounted thereon opposite said slots, a backing plate for said base, an operating bar pivoted at the back of said plate and extending forwardly thereof, and means for loosely and detachably connecting said member to said operating bar.

14'. A switching unit comprising a supporting plate, an operating bar pivoted at the back and extending in front of said plate, an insulating carrier reciprocably mounted in front of said plate, means for loosely and detachably connecting said carrier to said bar, contact fingers mounted on and extending from said carrier in the direction of movement thereof, and stationary contacts bridged by said contact fingers.

'the vertical wall oi. the base adjacent to the cutaway portion having a plin'a'lity of slots therein extending to the top of the .base and to the level of the cut-away portion, the entrance to said slots being a restricted open= ing to provide for are suppression, curved por= tions on the walls-bounding said slots, contacts fixed to the base and extending into certain of said slots, a cover member for said base, eon= tacts carried by said cover and extending into other of said slots, all of said contacts being curved about the curved walls be the slots, adjaeer cent contacts on the base and cover being separated by the walls between the slots and engaged by the fingers of the U-shaped contact member inserted through said restricted openings,

16. A switching unit including an insulating base member having slots therein, a stationary contact member disposed in each of said slots, a reciprocable insulating member having contact fingers mounted thereon opposite said slots, a backing plate for said base, an operating bar pivoted at the back of said plate and extending forwardly thereof, means for loosely and detachably connecting said member to said operating bar, and means for mounting said unit in a cabinet forwardly of the rear wall thereof, said unit being bodily removable to provide access to the cabinet interior.

17. A switching unit including aninsulated base member having slots therein, a stationary contact member disposed in each of said slots, a reciprocable insulating member having con-;

tact fingers mounted thereon opposite said slots,

a backing plate for said base, an operating bar pivoted at the back of said plate and extending forwardly thereof, means for loosely and detachably connecting said member to said operating bar, a cabinet comprising an open-front, boxlike body portion, a narrow strip extending alongreadily removable insulating plate engageable with said member to substantially close said slots while providing for entrance openings thereto, a stationary contact in-each ofsaid slots, a reciprocable insulating support, a U-shaped movable contact mounted on said support opposite said entrance openings, and mechanism for reciprocating said support to move the legs of said U-shaped contact into and out of the slots and bridging relation with said stationary contacts.

19. An electric switch comprising an insulating member, a plurality of slots in said member, a readily removable insulating plate engageable with said member to substantially close said slots while providing for entrance openings thereto,- a. stationary contact in each of said slots,-a reciprocable insulating support, a U- shaped movable'contact mounted on said support opposite saidentrance openings, and mechanism for reciprocating said support to move the legs of said il-shaped contact into and out of the slots and bridging relation with said stationary contacts, the entrances to said slots being restricted to facilitate arc suppression.

20. an electric switch comprising an insulating member, a plurality of pairs of slots in said member, a readily removable insulating plate engageable with said member to substantially close said slots while providing for entrance openings thereto, a stationary contact in each of said slots, .2. reciprocable insulating support, a iJ-shaped movable contact mounted on said support opposite said entrance openings, and mechanism for reciprocating said support to move the legs of said iJ shaped contact into and out of the slots and. bridging relation with said staing restricted to facilitate arc suppression.

21. In a switching device, a cabinet, mounting posts extending forwardly of the back of the cabinet, a supporting plate mounted on' said posts, a switching unit supported on said plate,

-an operating element pivotally mounted on a stationary part of said cabinet, means for readily detachably connecting said element to said unit, said plate being readily detachable from said posts to permit said unit to be removed from the cabinet interior to facilitate the wiring operation.

22, In-a switching device, a cabinet, an operating handle pivotally mounted on a stationary part of said cabinet, a switching unit mounted in said cabinet forwardly of the rear wall thereof to provide a wiring space, means for readily detachably connecting said handle to said unit, said unit being bodily removable from said cabinet and handle to uncover the wiring space.

23. In a switching device, a cabinet, a switching unit mounted in said cabinet forwardly of the rear wall thereof to provide a wiring space, an operating element pivotally mounted on a stationary part of said cabinet, quick make and break contact operating mechanism mounted on said unit, said unit and mechanism being bodily removable from said cabinet and element to uncover the Wiring space.

24. In a switching device, a cabinet, a switching unit mounted in said cabinet and including stationary and movable contacts and a pivoted bailshaped operating member for said movable contacts, a disc pivotally mounted on said unit and having an operative connection with said arm, a second disc pivotally mounted on said unit and having a lost motion connection with said first mentioned disc, an overcenter operating spring connected to said second disc, an operating handle pivotally mounted on a stationary part of said cabinet, and a lost motion connection between said handle and said second disc, said last connection being readily detachable to permit said unit and the parts carried thereby to be bodily removed from the cabinet.

25. An electric switch comprising a pair of substantially parallel contact elements, a pair of contact faces adapted to cooperate therewith, insulating means substantially enclosing said contact faces and having a generally central portion disposed betweensaid contact elements, said insulating means having restricted openings in one direction only to relatively closely receive said contact elements and functioning to-quench any are drawn between said elements and faces, one pair being integrally joined and serving to electrically connect the; cooperating pair, said pairs being relatively,movable-rectilinearly to connected and disconnected positions, and means for causing such rectilinear movement to effect the switching operation. I

26. An electric switch comprising a plurality of pairs of substantially parallel contact elements, a plurality of pairs of contact faces adapted to cooperate therewith, insulating formations substantially enclosing said contact faces and providing individual slots each relatively closely receiving but one of said elements and limitingthe relative movement between said elements and insulating formations to a straight line rectilinear movement, said formations serving to effectively quench any arc drawn between said pairs of contact faces and contact elements, one pair in each cooperating set of pairs being electrically common, and means for rectilinearly moving said electrically common pairs into and out of engagement with their cooperating pairs'to make and break the circuit through the switch.

27. An electric switch comprising a plurality 5 of pairs of substantially parallel contact elements. a plurality of pairs of contact faces adapted to cooperate therewith, insulating formations substantially enclosing said contact faces and providing individual slots each relatively closely receiving but one of .said elements and limiting the relative movement between said elements and insulating formations to a straight line rectilinear movement, said formations serving to effectively quench any are drawn between said pairs of con tact faces and contact elements, one pair in each cooperating set of pairs being electrically common, a pivotally mounted crank element, means operatively connecting said electrically common pairs to said crank element, and means for rotat- 2 ing said crank element to efiect rectilinear movement of said electrically common pairs into and out of engagement with their cooperating pairs.

28. An electric switch comprising a plurality of pairs of substantially parallel contact elements, a plurality of pairs of contact faces adapted to cooperate therewith, insulating formations substantially enclosing said contact faces and providing individual slots each relatively closely receiving but one of said elements and limiting the relative movement between said elements and insulating formations to a straight line rectilinear movement, said formations serving to effectively quench any are drawn between said pairs of contact faces and contact elements, one pair in each cooperating'set of pairs being electrically common, a pivotally mounted crank element, means operatively connecting said electrically common pairs to said crank element, and means for rotating said crank element to effect rectilinear movement of said electrically common pairs into and out of engagement with their cooperating pairs, said means including an operating handle, an element having lost motion connections with both the handle and crank, and an overcenter spring connected to said element to cause the 4 movement of said crank and movable pairs to be snap-like in action.

29. In an electric switch, spaced stationary contact elements, a rectilinearly movable contact element adapted to bridge said stationary contact elements, an insulating member carrying said movable contact element, a metallic bracket secured to said insulating element, an operating crank, said bracket loosely and removably engaging said crank to permit self-adjustment of the insulating member and movable contact relative to the stationary contacts during the switching operation, and operating mechanism for rotating said crank, the insulating member and movable contact moving rectilinearly into and out of engagement with the stationary contacts in response to movement of said crank.

30. In an electric switch, spaced stationary contact elements, a movable contact adapted to bridge and electrically connect said stationary contact elements, a carrier for said movable contact formed of insulating material, a metallic bracket secured to said carrier, an operating crank, said bracket loosely and removably en 7 gaging said crank to provide for limited adjusting movement of said carrier relative thereto and for removal and replacement of carriers and contacts, and operating mechanism for rotating said crank to effect rectilinear movement of the car- 50 movable contact cooperable therewith, a carrier rier to engage and disengage said movable contact with the stationary contact elements to make and break the circuit through the switch.

31. In an electric switch for industrial control service, insulating formations forming a contact chamber having at least an entrance open-.-

ing leading thereto, a stationary contact mounted inside the chamber from one wall thereof, a movable contact cooperable therewith, a carrier assembly mountingthe movable contact and having a part extending through the opening to carry the movable contactwith a translating motion to and from engagement with the stationary contact, said chamber being of sectional construction, means on one of the sections for attaching the sameto a support, anotherof said sections having as part thereof the wall upon which the stationary contact is mounted, and a readily separableconnection between said'sections so that said lastmentioned section is readily separablefrom said first named section without disturbing said first named section.

132. In an electric switch for industrial control service, insulating formations forming a contact;

'chamber havingat least an entrance opening leading thereto, a stationary contact mounted inside the chamber from one wall thereof, a'movable contact cooperable therewith, a carrier 'ass'enTbIy mounting the movable contact and 'having a part extending through the opening to carry the movable contact with a translating motion to and from engagement with the stationary contact, said insulating formations and chamber being of sectional construction, a metalback plate for supporting .said insulating formations to fix the contact chamber and stationary contacts in position, means on one of the sections for attaching the same to said metal back plate,

another of said sections having as part thereof the wall upon which the stationary contact is Y mounted, and a readily separableconnection between'said sections so that said last namedsection isreadily separable from'said first named section without disturbing said' first named section.

33. In an electric switch for industrial control service, insulating formations forming a contact chamber .having at least an entrance opening leading thereto, a stationary contact mounted inside the chamber from one wall thereof, a

assembly mounting the movable contact and. having a part extendingthrough the opening to carry the movable contact with a translating motion to andfrom engagement with the stationary contact, said insulating formatiom-and chamber being of sectional construction, a metal back plate for supporting said insulating formations to fix the contact chamber and stationary contacts in position, means on one of the sections for attaching the same to said metal back plate,

another of said sections having as part thereof the wall upon which the stationary contact is.

mounted, a readily separable connection between said sections so that said last named section is readily separable from said first named section without disturbing said first named section, switch-operating means also supported on said metal back plate, and means for removably mounting said metal platewithin a switch enclosing'cabinet.

34. In an electricswitch for industrial control service, insulating formations cooperating to form. a contact chamber having an entrance opening leadingthereto from the bottom thereof, a stationary contact mounted inside the chamber from one wall thereof, a movable contact surface cooperating withsaid stationary contact within the chamber, a carrier assembly substantially beneath said contact chamber and mounting the movable contact surface including means extending through the entrance opening; and car- 'rying the movable contact surface with a translating motion'to and from engagement with the stationary contact, said chamber being of sectional construction, meanson one of the sections for attaching the same to a support, another of said sections having as part thereof the wall upon which the stationary contact is mounted,

and a readily separable connection between said sections so.that said lastnamed section is readily separable from said first named section without disturbing said first named section.

35. In an electric switch forindustrial control service, insulating formations cooperating to form a contact chamber. having an. entrance opening leading thereto from the bottom thereof, a stationary contact mounted inside the chamberfrom one wall thereof, a movable contact surface cooperating with said stationary contact within the chamber, a carrier assembly substantially beneath said contact chamber and mounting the movable contact surface including means extending through the entrance opening and car- .named section is readily separable from said first named section without disturbing said first named section, and switch operating m'eans also supported on said metal back plate and beneath said carrier assembly for effecting the translating movement of the contact surface to effect the switching operation.

36. In an electric switch for industrial control service, insulating formations cooperating to form a'plurality of isolated contact chambers having entrance openings leading thereto from the bottom' thereof, stationary contact means mounted within said chambers from a common wall thereof, movable contact means cooperating with said stationary contact means within said movable contact means for translating movement to and from engagement with the stationary contact means, said carrier assembly and movable contact means including means extending through the entrance openings into the chambers, saidinsulating formations being of sectional construction with means on one-of the sections for attaching the same to a support,

another of said sections having as part thereof the wall upon which the stationary contact means are mounted, and a readily separable connection between said sections so that said last named section is readily separable from said first named section without disturbing said first named section.

JOHN G. JACKSON.

' rying-the movable contact surface. with a trans:

the chambers, carrier assembly means mounting Disclaimer 2,143,697.John G. Jackson, Detroit, Mich. ELECTRIC SWITCHING DEVICE. Patent dated Jan. 10, 1939. Disclaimer filed Dec. 31, 1948, by the assignee,

Square D Company. Hereby enters this disclaimer to claims 31, 32, 33, 34, 35, and 36 in said specification.

[Ojficial Gazette February 22, 1949.]

Disclaimer 2,143,697.J0Im G. Jackson, Detroit, Mich. ELECTRIC SWITCHING DEVICE. Patent dated Jan. 10, 1939. Disclaimer filed Dec. 31, 1948, by the assignee, Square D Company. Hereby enters this disclaimer to claims 31, 32, 33, 34, 35, and 36 in said specification.

[Ofiicial Gazette February 22, 1949.] 

